Moi Meng Ling, Lim Chang-Kweng, Kotaki Akira, Takasaki Tomohiko, Kurane Ichiro
Department of Virology I, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, Japan.
Clin Vaccine Immunol. 2010 Mar;17(3):402-7. doi: 10.1128/CVI.00396-09. Epub 2009 Dec 30.
Protective immunity against dengue virus (DENV) is best reflected by the presence of neutralizing antibodies. The conventional plaque reduction neutralizing test (PRNT) is performed using Fcgamma receptor (FcgammaR)-negative cells. Because FcgammaR plays a key role in antibody-dependent enhancement, we examined neutralizing antibody titers of mouse monoclonal antibodies and human serum samples in PRNTs using FcgammaRIIA-negative and FcgammaRIIA-expressing BHK cells. There was a discrepancy in dengue virus neutralizing antibody titers between PRNTs using FcgammaRIIA-negative versus FcgammaRIIA-expressing BHK cells. Neutralizing antibody titers to DENV-1 and DENV-2 tested with monoclonal antibodies, and with most of the human serum samples, were higher in assays using BHK cells than those using FcgammaRIIA-expressing BHK cells. The results suggest that neutralizing antibody titers determined using FcgammaRIIA-expressing cells may better reflect the protective capacity of anti-DENV antibodies, as the major target cells of DENV infection are FcgammaR-positive cells.
对登革病毒（DENV）的保护性免疫最好通过中和抗体的存在来体现。传统的空斑减少中和试验（PRNT）是使用缺乏Fcγ受体（FcγR）的细胞进行的。由于FcγR在抗体依赖性增强中起关键作用，我们在使用缺乏FcγRIIA的BHK细胞和表达FcγRIIA的BHK细胞的PRNT中检测了小鼠单克隆抗体和人血清样本的中和抗体滴度。在使用缺乏FcγRIIA的BHK细胞与表达FcγRIIA的BHK细胞的PRNT之间，登革病毒中和抗体滴度存在差异。用单克隆抗体以及大多数人血清样本检测时，针对DENV-1和DENV-2的中和抗体滴度在使用BHK细胞的试验中高于使用表达FcγRIIA的BHK细胞的试验。结果表明，由于DENV感染的主要靶细胞是FcγR阳性细胞，因此使用表达FcγRIIA的细胞测定的中和抗体滴度可能更好地反映抗DENV抗体的保护能力。
